How does spreading work?

I was thinking about Fred Fuller's post in another thread about his buckshot load not spreading so much and I asked myself:

How does spreading work exactly?

What makes a brand spread faster than another?

Is there a correlation between speed, shot size, shot density, shot hardness, shotgun gauge, barrel length or other variables and spreading?

Well, all I know about it is that the choke makes a very real difference in shot spreading and pattern.

What about these other variables?

Thank you for your continuous efforts in educating me:)

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oneounceload

June 13, 2014, 09:12 PM

Choke constriction is the major factor in how a pattern works from a shotgun

rule303

June 13, 2014, 09:20 PM

Barrel length doesn't make any difference. Shot hardness and uniformity, as well as wad design can make a difference almost as much as choke constriction. Shot buffering, powder burn rate, and shell crimp can all make small changes in pattern. Generally, a larger the bore size will pattern more evenly given the same amount of shot.
Shooting different loads at a pattern board will tell you that when it comes to shotgun patterns, nothing is set in stone. Sometimes you will get a tighter pattern with a modified choke than a full, and some guns will throw a beautiful pattern with a load that is a mess fired from another gun of the same gauge and choke constriction.

Frostbite

June 13, 2014, 09:26 PM

Sometimes you will get a tighter pattern with a modified choke than a full

With the same shotgun and with the same ammo??? Surprising!

rcmodel

June 13, 2014, 09:32 PM

There have been spreader loads in the past, and still are for hunting that included 3 or more card wads in the shot column.

Or, plastic wads with a post in the middle of the shot.

It causes the shot column to disperse sideways faster the normal after it comes out of the choke.

I'm not aware of any for buck-shot though.
Current thinking with buck-shot is the tighter the pattern, the better!

rc

Frostbite

June 13, 2014, 09:39 PM

Current thinking with buck-shot is the tighter the pattern, the better!

I could not agree more with regards to my hunting. I would not want bullets everywhere in the good parts.

Is it the same for the HD users or is it perceived as the wider the better, as in less chance to miss under stress?

Fred Fuller

June 13, 2014, 10:03 PM

Is it the same for the HD users or is it perceived as the wider the better, as in less chance to miss under stress?

There are about as many opinions regarding buckshot patterns as there are shotgun shooters. Maybe more: D.

I think everyone should work to get whatever kind of pattern they want, for the particular purpose or purposes they have in mind. Open, medium or tight, whatever a person's preference is, for whatever reason, they should look for the combination of internal barrel geometry and buckshot load that produces what they want as reliably as possible.

Choke is indeed one factor, but there are many, many more. An extended, polished forcing cone seems to help a lot to improve shotgun patterns with larger shot, in my experience and that of Dave McC, our esteemed late moderator here. Hans Vang made his name decades ago by overboring short open choked riot gun barrels and leaving in a few points of choke as original barrel diameter at the muzzle. Sometimes he put in ports too, but I don't think those helped with patterns. My gunsmith when I was a kid, Ralph Walker of Selma, AL, experimented a lot with what was called 'jug choking' (opening up the bore of a CYL bore barrel behind the muzzle for a short distance) and was an early adopter of choke tubes. A tight choke, however, will not necessarily guarantee tight patterns - often enough, the opposite is true as an overly tight choke will distort pellets as they pass through it, inducing spread.

In my experience the load matters a lot. A major factor in inducing spread in a buckshot pattern is pellets that get out of round in their trip down the bore. Some of them come out looking positively faceted, especially pellets made of dead soft lead with no hardening alloys added, or no plating with harder metals like copper or nickel. Lack of buffering (grex), lack of a protective shot collar or wad cup, and lack of a cushioning wad column to ease the blow of firing also are factors in avoiding pellet deformation in the short trip down the bore.

So - want open patterns? Shoot the inexpensive stuff with soft lead pellets and little or no pellet protection - Rio Royal, S&B etc.

Want tight patterns? Look for a "premium" load, preferably one with a FliteControl wad (see http://www.federalpremium.com/education/flitecontrol.aspx for more info). Premium loads are likely to have hard lead alloy pellets, plated with a harder metal like copper, protected with granulated plastic, shot cups or collars, and good, shock absorbing wad columns.

All the factors above are likely to influence patterns as described - but there are no guarantees. Shotgun patterns are as much magic as science sometimes, it seems. A dedicated shooter will try a variety of loads, chokes, barrels etc. to get what he or she wants out of a shotgun as far as patterns are concerned. And the only way to really tell, is at the patterning board.

See http://www.youtube.com/watch?v=_pIuUrjUIyQ#t=472

As far as using pattern spread to make up for lack of shooter ability ... well, it's always seemed to me that hitting was the SHOOTER'S responsibility, not the shotgun's. I often say that there are no hardware solutions to software problems. Others may disagree with that idea, as is their prerogative. I am a firm believer in taking advantage of the training that is widely available these days, from a number of well qualified professional instructors. That seems to be another point of contention with a lot of shooters as well.

Steve C

June 13, 2014, 11:03 PM

The choke of the barrel is the major factor in shot spread.

Hard shot deforms less and holds a tighter pattern than shot that's less hard.

Lower the velocity, the tighter the pattern assuming equal components.

The components used in the shell assembly will effect the size of the pattern at distance significantly. Wads and/or buffering material are very important with a plastic wad or buffer material that encloses the shot and protects it from deformation giving tighter patterns than shells that don't have good wads and buffers. Federal fight control wads produce very tight patterns for example when compared to other shells with simple base wads that don't cushion the shot or keep it together.

Other factors have little influence on amount of spread.

Fred Fuller

June 13, 2014, 11:17 PM

The choke of the barrel is the major factor in shot spread.

Not any more... FliteControl technology has put an end to that.

It's as much of a myth as "You can't miss with a shotgun."

LeonCarr

June 14, 2014, 12:25 AM

Hey Frostbite,

Here is some testing I have done on Buckshot, and the commentary included might help you understand what makes buckshot spread or not spread. Choke is a factor, but not the whole story:

I was thinking about Fred Fuller's post in another thread about his buckshot load not spreading so much and I asked myself:

How does spreading work exactly?

What makes a brand spread faster than another?

Is there a correlation between speed, shot size, shot density, shot hardness, shotgun gauge, barrel length or other variables and spreading?

Well, all I know about it is that the choke makes a very real difference in shot spreading and pattern.

What about these other variables?

Thank you for your continuous efforts in educating me
__________________

All of those questions were answered by Bob Brister in his classic study of shotguns and patterns: "Shotgunning: The Art and Science"
It is true, however, that more modern technigues at the factory have improved the uniformity and efficiency of some types of shells.
Regardless, ya still need to pattern your gun.
Pete

Fred Fuller

June 14, 2014, 01:32 PM

Regardless, ya still need to pattern your gun.
Pete

Pete wins the Intarnetz...

Frostbite

June 14, 2014, 06:05 PM

Thank you gentlemen for taking the time to share your knowledge and answer these questions which must sometimes seem basic to you, judging by the quality of many of the answers posted :)

Some of you provided good explanations on a technical level, some of you provided useful guidance in ammo selection. That is exactly what I was after. I like both to understand why and what to look for.

I would not have suspected that much difference between different ammo such as what has been measured by LeonCarr's experimentation. I also found it interesting both because many different loads have been tested and because his test shotgun is in some ways similar to mine: short barreled and cylinder choked.

Shotgunning: The Art and Science, by Bob Brister, will appear on my Summer (understand leisure) reading list. Not sure if I will find it over here. It might be wise to check for it next time I visit the States. I will also check the web, we never know what can be found out there :rolleyes:

As previously posted in another thread, I have already experimented with three different buckshot loads. Sadly, I only recorded the fun associated with that painful shooting session, which was immediately preceded by twenty slugs in less than half an hour. Testing will continue. Measuring will be more precise. Number of shots fired shall be smaller for each kind of ammo. No way I will shoot twenty slugs in a row before I get to the buckshot testing ever again. I am not particularly shoulder sensitive, but there are limits to what I can enjoy :banghead:

I will keep in mind the quick guide Fred Fuller provided for opened, medium and tight patterns associated with the kind of ammo. It gives a good idea what to look for when at the ammo counter: premium stuff in my case. Do you think the reduced recoil stuff has enough punch for deer? Visiting Federal's website proved useful in understanding the mechanic of their FliteControl ammo. Thanks for the link. Just sad it seems I will have to go the more expensive route; LeonCarr's experimentation also pointed that way. :(

I had just ordered a bunch of Challenger 2¾" 00 buckshot. Federal will have to wait for more ammo money. :neener: Can't wait to see how it patterns out of my shotgun! Does any of you have any experience with those? Did they perform well? Did they spread a lot?

Pete D.

June 15, 2014, 06:31 AM

Frostbite: You are in Quebec? You should have no trouble finding Brister's book.
Amazon sells it.
Also...more reading...John Brindle's "Shotgun Shooting: Techniques and Technology" is a worthwhile addition to your bookshelf.
Note: recent technology has changed so much that some of what is in these books has is now "old info".....not wrong info but supplanted by change. Flite control is an example. (Most shotshells available today, however, are not "flite controlled")
Pete

SeekHer

June 15, 2014, 09:37 AM

The choke of the barrel is the major factor in shot spread.

Not any more... FliteControl technology has put an end to that.

It's as much of a myth as "You can't miss with a shotgun."
Except that the pattern will be different at the same distance--even with Flight Control-- when coming out of a IC, Mod or a Full choke barrel...So choke still dictates spread.

Breaking Clays and
The Instinctive Shot: The Practical Guide to Modern Wing Shooting both by Chris Batha

The Shotgun: A Social History by Macdonald Hastings

Really old info but classics none the same.
Shotguns by Keith by Elmer Keith

Shotgun Stuff and
The Double Shotgun both by Don Zutz

Fred Fuller

June 15, 2014, 12:37 PM

The assumption has historically been that a tight choke is necessary for tighter patterns.

That is the myth FliteControl has pretty much put to rest.

it is certainly true that in some cases if not many cases, using tighter chokes with FliteControl will cause more open patterns rather than tighter patterns.

And regardless of any of the above generalizations, the one certainty is that you must pattern your gun and load to have any idea what it will do at a given range.

Frostbite

June 15, 2014, 08:05 PM

Thank you guys for the reading advices. I will search for these books; I like to learn. Often times, one does not know where to start when entering a new field of knowledge. I will take it that these books are such a place.

Fred Fuller seems sold to the idea of the FliteControl. Given the results of LeonCarr's experiments, I can easily understand why. rcmodel mentioned that the spreading loads were mostly used in a hunting context.

I do no think that a spreading load for white tail deer hunting is the preferable choice, because I fear some meat would be lost because of it. I would like to know what you think of the FliteControl load for that particular hunt. Would it be a good choice in your opinion?

rcmodel

June 15, 2014, 08:29 PM

For any deer hunting with buckshot, the tighter the pattern the better!

Assume you have 9 00 buckshot in a load.

Would you rather hit the deer in the chest kill zone with all 9 of them?

Or one in the leg, one in the chest, one in the neck skin, one in the guts, and the other five complete misses?

rc

SeekHer

June 15, 2014, 10:50 PM

Well, actually spreader loads were designed to open up when fired from tight choked guns before the advent of screw-in chokes.

Shooting doves with a M/F double didn't result in many kills compared to an IC/M but the only way to increase spread was either an expensive, permanent, gunsmith modification (either boring out or installing a Vari-Choke)or spreader shells.

For deer hunting, you're far better off with slugs.

lemaymiami

June 16, 2014, 08:57 AM

All of my shotgun experience (98%) was with police shotguns...standard rack grade riot configured Mossbergs and Remingtons (for "riot configured", read bead sight, four round tube, barrel length between 18 and 20", with a cylinder or improved cylinder barrel, using Winchester or Remington standard 2 3/4" nine pellet 00buck ammo....). The exercise/demonstration that stuck with me throughout the years was a very simple patterning exercise that anyone can duplicate...

Set up three or four simple paper targets - all at the same height, the first at 3 yards, the second at 7, the next at 15, the last at 20yards -all in a row, one after the other. If you can manage to level out so that your weapon is parallel to the ground, then fire a single shot with buck you'll end up with a very graphic and usable set of guidelines that show clearly just how important distance from the target is with a shotgun loaded with buckshot.... You'll also see demonstrated just how much a charge of buck will rise a bit as it goes downrange, those first 20 yards...

We pretty much expected that buckshot to disperse about one inch per yard (or meter if you prefer) from the muzzle. At seven yards the pattern was predictably right at seven inches... This whole business of how much a given load will disperse downrange is critical in the real world since it governs how effective you can be in an armed conflct at close quarters...

If it were me, I'd want to do this with each and every shotgun I had access to and I'd want to check out each and every ammo type that I'd be using. If you know exactly how your popper will perform when needed it really builds confidence that you can use it effectively on the one day when everything is at stake....

To reach the next level you'll want to learn how to skip shoot (bounce your shot off of a surface before it hits your target) - but that's another topic entirely....

Pete D.

June 20, 2014, 09:13 PM

We pretty much expected that buckshot to disperse about one inch per yard (or meter if you prefer) from the muzzle. At seven yards the pattern was predictably right at seven inches

That is pretty much a classic formula. One inch per yard from a FC, two inches per yard from an Cyl choke.

Fred Fuller

June 21, 2014, 10:59 AM

That is pretty much a classic formula. One inch per yard from a FC, two inches per yard from an Cyl choke.

That WAS a classic formula.

My current house gun will print patterns of about 4" (four inches) at 25 yards (75 feet) out of a factory 18" CYL bore 870 shotgun barrel with Federal LE 127 00 with FliteControl.

When FliteControl first appeared, some gun scribes complained that its patterns out of off-the-rack riot guns were TOO tight... no such thing, IMO, but YMMV.

Pete D.

June 22, 2014, 06:25 AM

Fred: I follow your point about Flite Control technology. Such a pattern at 25 yards is remarkable and for that use desirable....

but about pattern spread in general...
That WAS a classic formula.

Still is for most loads.....most shotshells are not Flite controlled. There are many instances where a small pattern such as you describe would be a handicap. Ruffed Grouse in the huckleberries comes to mind.....a hard right on station five is another.
Pete

Fred Fuller

June 22, 2014, 01:34 PM

There are many instances where a small pattern such as you describe would be a handicap.

Not with a CYL choke barrel ... :D ... all ya gotta do to open things up is swap shells. Not even any need to spin choke tubes in and out.

I do love tight patterns, but there's a stash of S&B 00 buck here too, in case a 'to whom it may concern' situation arises. Everyone always says versatility is the shotgun's strong point ... no need to fight that particular shibboleth when you can use it to your advantage!

And by the way, I have two or three 18.5" rifle sighted 870 factory barrels with fixed MOD chokes here also, in case FliteControl gets hard to find. There are several buck loads that do well for me out of a MOD barrel. I used one of these at my last shotgun class, where we were shooting 'negative' targets (cardboard IPSC silhouettes with an 8" hole cut out of the center). It was easy to slip birdshot and buckshot patterns through the hole from the firing line and not rag out the cardboard, unless you flat out missed the hole.

See http://www.midwayusa.com/product/921370/remington-barrel-remington-870-12-gauge-3-18-1-2-fixed-modified-choke-with-tritium-rifle-sights-parkerized?cm_vc=ProductFinding

Pete D.

June 22, 2014, 05:29 PM

all ya gotta do to open things up is swap
I see your point. Wasn't thinking that way.
Pete

Frostbite

June 22, 2014, 07:05 PM

Everyone always says versatility is the shotgun's strong point

That is the main reason why I bought my twelve gauge pump shotgun. Secondary justification was that I did not have one!

I6turbo

June 23, 2014, 10:29 AM

Great input from Fred Fuller and others here, the absolute best of which is that you really don't know what your gun/load combo might be doing unless you pattern it. I used to do a TON of patterning and load development for my 12 and 20 ga. shotguns, both of which had 26" IC and Modified chokes. With patterning and load development work you can make about any choke do about anything that you need, within reason. Juggling shot size, shot weight, wads, powder charge, and hulls, you can very dramatically alter the on-target results. IME, there is waaay more to be gained in load development for a shotgun than a rifle or pistol.

RMc

June 25, 2014, 10:18 AM

"...with a CYL choke barrel ... ... all ya gotta do to open things up is swap shells. Not even any need to spin choke tubes in and out.
I do love tight patterns, but there's a stash of S&B 00 buck here too, in case a 'to whom it may concern' situation arises. Everyone always says versatility is the shotgun's strong point..." Fred Fuller

Excellent observation on the cylinder bore!

With the development of the Flite-Control wad, choke has been literally built in to the wad. Thus the classic cylinder bore riot gun can now fire tight long range buckshot patterns or wide open hallway distance patterns with just a change of ammo.

Fred Fuller

June 25, 2014, 11:04 AM

I read once about commercially prepared shot charges that were available a long time ago, back in the muzzleloading era, for muzzle loading shotguns. The shot charges were packaged in fine wire (copper, I think it was) mesh 'cages' that contained the shot to some degree and limited spread over distance. So the concept behind FliteControl is not really new. But the execution of it, as allowed by self-contained cartridges and repeating shotguns, is definitely a current development ... and a concept we all need to adopt the appropriate mindset to use to maximum advantage.

4thPointOfContact

June 25, 2014, 12:21 PM

Patterns can vary. I can get anywhere between 4-5 inches @ 25 yards with FliteControl (Federal LE 127 or LE 132) up to 8-feet at 15 yards (gimmick flechette rounds I got at a gun show just to test). Both patterns out of the same gun.

I love the Federal stuff, but indoors I have Fiocchi 12HV4BK in the translucent shells, just because I want a little more spread.

2zulu1

June 25, 2014, 01:16 PM

That is pretty much a classic formula. One inch per yard from a FC, two inches per yard from an Cyl choke.

That WAS a classic formula.

My current house gun will print patterns of about 4" (four inches) at 25 yards (75 feet) out of a factory 18" CYL bore 870 shotgun barrel with Federal LE 127 00 with FliteControl.

When FliteControl first appeared, some gun scribes complained that its patterns out of off-the-rack riot guns were TOO tight... no such thing, IMO, but YMMV.
As you eloquently wrote, this ammunition is a game changer because the wad holds the buck shot together for at least 20-25 yards out of my FNH SLP. With dialed in C-MORE on top, pop cans at 20-25 yards are routinely hit, even by those who have never fired a shotgun. Put a paper target on plywood and the wads are either sticking out of the target or they are on the ground below.

At home defense distances, flight control buckshot removes the need for using slugs against felonious intruders.

At 10yds, empty 10 gallon propane tanks are fully penetrated with a large hole that is surrounded by a very large dimple.

Pete D.

June 26, 2014, 08:10 AM

I just spent some time reading up on the Flite Control technology. Impressive.
I wish that I could get my hands on a bag of those wads.
Unfortunately, Federal offers little that I can use with the FC wads..... unless I missed something.
Most of my shooting is ATA Trap singles (FC would be helpful for handicap loads) and Upland hunting. Did not see anything that would be useful... but if I could hand load them....
Pete

RMc

June 27, 2014, 07:27 PM

I read once about commercially prepared shot charges that were available a long time ago, back in the muzzleloading era, for muzzle loading shotguns. The shot charges were packaged in fine wire (copper, I think it was) mesh 'cages' that contained the shot to some degree and limited spread over distance. So the concept behind FliteControl is not really new. But the execution of it, as allowed by self-contained cartridges and repeating shotguns, is definitely a current development ... and a concept we all need to adopt the appropriate mindset to use to maximum advantage.
Indeed so! Here is a reference to one such patented shot concentrator from the 1820's.